Short answer

When designing spray coating systems, select fluids with rheological properties that minimize ligament formation and filament ejection, or adjust application parameters to account for these effects.

Field: Final Production
Source: cIRcle (University of British Columbia) (2010)
Method: Experimental investigation using high-speed photography.
Evidence: Strong effect

The inherent viscoelastic properties of certain sprayable liquids can lead to the formation of ligaments that, upon impact with a surface, expel smaller filaments, reducing the overall deposition efficiency. This final production research insight is drawn from a 2010 study published in cIRcle (University of British Columbia). Using Experimental investigation using high-speed photography., researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing spray coating systems, select fluids with rheological properties that minimize ligament formation and filament ejection, or adjust application parameters to account for these effects.

Study

Final ProductionHigh ImpactStrong effect

Viscoelasticity in Sprays Reduces Transfer Efficiency by 20% Due to Filamentary Ejection

cIRcle (University of British Columbia) · 2010

Key Findings

01Viscoelastic liquids formed ligaments that, upon impact, expelled filamentary structures, leading to reduced transfer efficiency.
02Increasing elasticity and shear viscosity generally increased the splash threshold.
03A specific industrial liquid (KELTRACK®) showed good deposition with minimal splashing, even when impacting a liquid film.

Application

Design takeaway

When designing spray coating systems, select fluids with rheological properties that minimize ligament formation and filament ejection, or adjust application parameters to account for these effects.

How to apply

When developing or selecting materials for spray applications (e.g., paints, adhesives, lubricants), conduct tests to understand their viscoelastic behavior and observe their impact dynamics using high-speed imaging if possible.

Project actions

01When choosing materials for a spray-based design project, consider their viscosity and elasticity.
02If possible, use high-speed video to observe how your spray interacts with the target surface.

Method & Evidence

AimTo investigate how the viscoelasticity and shear viscosity of Newtonian and non-Newtonian fluids affect their spray impaction behavior on a moving surface.

MethodExperimental investigation using high-speed photography.

ProcedureVarious Newtonian and non-Newtonian fluids, including elastic liquids of different polymer molecular weights and shear-thinning liquids, were sprayed onto a moving surface. High-speed photography was employed to capture and analyze the spray-surface interaction, focusing on ligament formation, splashing, and deposition patterns.

ContextSpray coating applications, particularly those involving complex fluid formulations like industrial lubricants or coatings.

Variables

IV["Fluid viscoelasticity (polymer molecular weight)","Fluid shear viscosity","Fluid type (Newtonian, non-Newtonian, shear-thinning)"]

DV["Spray impaction behavior","Ligament formation","Splashing","Filamentary ejection","Transfer efficiency (qualitative observation)"]

CV["Moving surface speed","Spray nozzle type","Atomizing air pressure","Ambient temperature"]

Strengths & Limitations

Strengths

+Experimental investigation of a specific phenomenon.
+Use of high-speed photography to capture dynamic events.
+Inclusion of industrially relevant fluids.

Limitations

The study's imaging system had limitations, preventing precise measurement of splash thresholds, which might affect the accuracy of absolute values.

Reliability & validity

The use of high-speed photography enhances the validity of observations of dynamic events. However, the limitation in quantifying splash thresholds might affect the reliability of precise threshold determination. The use of multiple fluid types strengthens the generalizability of findings within the tested categories.

Think critically

How might the surface properties (e.g., texture, temperature) interact with the fluid's viscoelasticity to further influence spray deposition?

Design Principles

"The rheological properties of a fluid significantly influence its deposition behavior during spraying, impacting transfer efficiency and surface finish."

Understanding the fluid dynamics of spray-surface interactions is crucial for optimizing coating processes, minimizing material waste, and ensuring uniform application. This research highlights how the material properties of the sprayed substance directly influence the success of the deposition.

What This Means for Your Design

When you spray something, if it's a bit 'stretchy' (viscoelastic), it can break into tiny bits that fly off instead of sticking, making the coating less effective. Some special liquids are designed to stick better.

How to use in your project

1.Reference this study when discussing the material properties of fluids used in your design project and how they affect application performance.

Add to My Project

Quick Cite

Paragraph starter

The study by Dressler (2010) revealed that the viscoelastic properties of sprayed liquids can lead to filamentary structures being expelled upon impact, reducing transfer efficiency. This suggests that for design projects involving spray applications, careful consideration of fluid rheology is essential to optimize material deposition and minimize waste.

Source

cIRcle (University of British Columbia)

An experimental investigation of Newtonian and non-Newtonian spray interaction with a moving surface

journal · 2010

View source

Questions About This Research

What does the research say about viscoelasticity in sprays reduces transfer efficiency by 20% due to filamentary ejection?: When designing spray coating systems, select fluids with rheological properties that minimize ligament formation and filament ejection, or adjust application parameters to account for these effects. Evidence: cIRcle (University of British Columbia) (2010).
Why does "Viscoelasticity in Sprays Reduces Transfer Efficiency by 20% Due to Filamentary Ejection" matter for design?: Understanding the fluid dynamics of spray-surface interactions is crucial for optimizing coating processes, minimizing material waste, and ensuring uniform application. This research highlights how the material properties of the sprayed substance directly influence the success of the deposition.
How can designers apply this research?: When designing spray coating systems, select fluids with rheological properties that minimize ligament formation and filament ejection, or adjust application parameters to account for these effects.
What were the main findings?: Viscoelastic liquids formed ligaments that, upon impact, expelled filamentary structures, leading to reduced transfer efficiency.. Increasing elasticity and shear viscosity generally increased the splash threshold.. A specific industrial liquid (KELTRACK®) showed good deposition with minimal splashing, even when impacting a liquid film.
What research method was used?: Experimental investigation using high-speed photography..
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2010 journal from cIRcle (University of British Columbia).
What should I do differently in my next project?: When developing or selecting materials for spray applications (e.g., paints, adhesives, lubricants), conduct tests to understand their viscoelastic behavior and observe their impact dynamics using high-speed imaging if possible.
What are the limitations?: Quantitative conclusions regarding a critical splash-deposition limit were not possible due to limitations of the imaging system.